The purpose of this application is to assess change and determinants of change in tobacco use for a population-based sample of California Korean immigrants. This proposal will assess longitudinal change in tobacco behaviors and predictors among a sample of 2,830 California residents of Korean descent who provided baseline data during telephone interviews completed from April 2001 through October 2002. Change in smoking status, change in environmental tobacco smoke (ETS) exposure, and change in the presence of and enforcement of residential tobacco policies (rules) will be assessed by an additional telephone interview about 45 months after the already completed baseline and a third telephone interview about 27 months later. This will provide about a four-year follow-up assessment of change in tobacco use among California Korean immigrants. A new cohort of 1,200 respondents will be recruited and interviewed at baseline and 27 months to assess the generalizability of our original baseline study results and to replicate short-term changes in tobacco use and the "determinants" of change in tobacco use. The project will explore the degree to which perceptions of current tobacco control programs, acculturation to U.S. society, exposure to mass and interpersonal media, and other variables derived from learning theory and its extension to the "Behavioral Ecological Model" are associated with changes in smoking cessation, initiation, home smoking policies, and adults' and children's ETS exposure. Particular attention will be devoted to the influence of the anti-tobacco media campaigns promoting smoking cessation and smoke-free homes. Results from this study will inform refinement of theory and interventions (including community-wide policies) for tobacco control with Korean and other immigrant populations. This application also requests support to pilot test a telephone counseling intervention to promote cessation and reduction in adults and children's ETS exposure in order to estimate effect sizes for a subsequent proposal. Data obtained in this pilot will inform research design for controlled trials of clinical services that might be delivered state-wide by telephone to the widely distributed Korean population. The combined analyses will inform tobacco control research for residents of Korean descent, who are a growing and underserved minority group in California and the U.S. It also will provide a model for delivering interventions to other Asian and minority populations distributed across larger geographic areas.